Flu Shot: Cochrane Collaboration Still Discourages It

Flu shots have been shown to be largely ineffective, but a financial boon for businesses that sell them.

It’s that time of year again for me to wrestle with the idea of getting a flu shot. It hasn’t been getting my vote. I base that vote on the work the of The Cochrane Collaboration, who are:

A global independent network of researchers, professionals, patients, carers, and people interested in health.

Cochrane contributors – 37,000 from more than 130 countries – work together to produce credible, accessible health information that is free from commercial sponsorship and other conflicts of interest. Many of our contributors are world leaders in their fields – medicine, health policy, research methodology, or consumer advocacy – and our groups are situated in some of the world’s most respected academic and medical institutions.

Our work is recognized as representing an international gold standard for high quality, trusted information.

Two things there … free from commercial interests and science-based. The buck stops with Cochrane. Here’s what they say:

After reviewing 90 reports of 116 studies, the largest collection of randomized evidence on influenza, they say it doesn’t do much good, and can cause harm:

The preventive effect of parenteral inactivated influenza vaccine on healthy adults is small: at least 71 people would need vaccination to prevent one case of influenza.

Vaccination shows no appreciable effect on working days lost or hospitalisation.

Myalgia is significantly associated with vaccination, as well as systemic fever, headache, fatigue or indisposition and malaise.

They outright discouraged its use a couple years ago (2010 study above), based on much of the same data, but I’m guessing some profit-making entity fought against such a straightforward conclusion:

The results of this review seem to discourage the utilisation of vaccination against influenza in healthy adults as a routine public health measure.

The reason you see signs everywhere for getting a flu shot, the reason you hear physicians recommending it, is because drug companies make money when people buy their vaccines. So, drug companies push these shots. They disseminate biased studies, many of which they fund, to health professionals and organizations:

This [Cochrane] review includes 90 studies, 24 of which (26.7%) were funded totally or partially by industry. Out of the 48 RCTs, 17 were industry-funded (35.4%).

From the 2010 study:

It is now known that industry funding of influenza vaccines studies determines publication in high prestige journals and higher citation rates than other types of funding. In addition industry funding is associated with optimistic conclusions.

Conclusions favorable to the use of influenza vaccines were associated with higher risk of bias. In these studies the authors made claims and drew conclusions unsupported by the data they presented. In addition, industry funded studies are more likely to have favorable conclusions and be published in significantly higher impact factor journals and have higher citation rates than non-industry funded studies. This difference is not explained by either their size or methodological quality.